//
//  MainTabBar.swift
//  
//
//  Created by IZEN on 16/3/6.
//
//

import UIKit

class MainTabBar: UITabBar {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(plusBtn)
    }
    

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    //自定义tabbar
    //addsubviews时 或subview的frame发生变化
    override func layoutSubviews() {
        super.layoutSubviews()
        
        let w = UIScreen.mainScreen().bounds.width / 5
        
        let h = self.bounds.height
        
        let rect = CGRect(x : 0, y : 0, width : w, height : h)
        
        //定义一个递增的索引
        var index : CGFloat = 0
        
        for subview in subviews {
            
            if subview .isKindOfClass(NSClassFromString("UITabBarButton")!){
            
                subview.frame = CGRectOffset(rect, index * w, 0)
                
                index += (index == 1 ? 2 : 1)

            }
            
            
        }
        addSubview(plusBtn)
        plusBtn.frame = CGRectOffset(rect, 2 * w, 0)
        
    }
    //MARK: 懒加载子视图
    lazy var plusBtn : UIButton = {
        
        let btn = UIButton()
        
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: .Normal)
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button_highlighted"), forState: .Highlighted)
        btn.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: .Normal)
        btn.setImage(UIImage(named: "tabbar_compose_icon_add_highlighted"), forState: .Highlighted)
        
        return btn
    }()
   

}
